avinash.kashyap
Junior Member level 3
As my previous post, this time also I haven’t done anything new for the experienced members but newbies might find this post very useful. I’ve made a USB AVR programmer to program ATmega and AT-89-S-51 series microcontrollers. This is based on the schematics available on the Fischl’s website, but I’ve done some changes after experimenting and have mentioned the changes between the Fischl’s diagram and the modified one.
Now, lets get down to the business, this is the schematic available on Fischl’s website,
The very next diagram is the modified version, which I’ve constructed. I’ve left the pins +5V and GND (from the 6pin output)on the diagram with tags only and these are to be connected to their respective places. And the output connector pins have been tagged as they are to be connected with the target chip’s respective pins.
The changes done:
On Fischl’s website the code is provided for ATmega8 and ATmega48 but I’ve used ATmega8L successfully with the same code as for ATmega8 and it makes it really cheaper and it also works great. Though datasheet says that ATmega8L’s limit is 8MHz crystal but in this programmer it’s working at 12MHz and working really well.
As other changes, the self programming jumper between pin 1 and pin 16 is completely removed, the 10 pin ISP output socket is modified to become a 6pin socket (because I basically needed 6 pin output), the slow SCK mode jumper from the pin 25 is also completely removed, the pins 20, 22 are disconnected, the 100n capacitor at pin7 is also removed.
I don’t recommend:
The programmer will continue to work if you remove the 4.7uF capacitor and the 3.6V Zener diodes but I’ll not suggest these changes as these might leave your programmer prone to any surges or fluctuations (from power’s end or device’s end) , even when we are feeding the programmer from the very steady USB port’s power, then too. (I would really like some experienced member to comment or share knowledge on this paragraph because my knowledge is very limited in this context.)
Now some photographs of the real construction,
Following are the board files in pdf format, designed by me,
View attachment USB ATmega Bottom Copper.pdf
View attachment USB ATmega Top Copper.pdf
(The size of the board is 28mmX60mm. Print the board as full, 100% or no scale or according to the similar option available with your printer.)
And this is the code which you have to burn on the ATmega8L chip. This code is taken from the Fischl's website, and is availabe there too, this is the link
https://fischl.de/usbasp
And this is the HEX File: View attachment usbasp.atmega8.2009-02-28.rar
This hex file has to be written on the chip. You can use following serial programmer to burn the hex file on the chip for the first time, it's very easy to make and would take only 20mins, even I used this for the first time,
AVR Programmer
I suggest you to visit Fischl's website for more designs which can be used with the same code available on Fischl's. You can use ATmega48, ATmega8 too.
So, happy burning...
Now, lets get down to the business, this is the schematic available on Fischl’s website,
The very next diagram is the modified version, which I’ve constructed. I’ve left the pins +5V and GND (from the 6pin output)on the diagram with tags only and these are to be connected to their respective places. And the output connector pins have been tagged as they are to be connected with the target chip’s respective pins.
The changes done:
On Fischl’s website the code is provided for ATmega8 and ATmega48 but I’ve used ATmega8L successfully with the same code as for ATmega8 and it makes it really cheaper and it also works great. Though datasheet says that ATmega8L’s limit is 8MHz crystal but in this programmer it’s working at 12MHz and working really well.
As other changes, the self programming jumper between pin 1 and pin 16 is completely removed, the 10 pin ISP output socket is modified to become a 6pin socket (because I basically needed 6 pin output), the slow SCK mode jumper from the pin 25 is also completely removed, the pins 20, 22 are disconnected, the 100n capacitor at pin7 is also removed.
I don’t recommend:
The programmer will continue to work if you remove the 4.7uF capacitor and the 3.6V Zener diodes but I’ll not suggest these changes as these might leave your programmer prone to any surges or fluctuations (from power’s end or device’s end) , even when we are feeding the programmer from the very steady USB port’s power, then too. (I would really like some experienced member to comment or share knowledge on this paragraph because my knowledge is very limited in this context.)
Now some photographs of the real construction,
Following are the board files in pdf format, designed by me,
View attachment USB ATmega Bottom Copper.pdf
View attachment USB ATmega Top Copper.pdf
(The size of the board is 28mmX60mm. Print the board as full, 100% or no scale or according to the similar option available with your printer.)
And this is the code which you have to burn on the ATmega8L chip. This code is taken from the Fischl's website, and is availabe there too, this is the link
https://fischl.de/usbasp
And this is the HEX File: View attachment usbasp.atmega8.2009-02-28.rar
This hex file has to be written on the chip. You can use following serial programmer to burn the hex file on the chip for the first time, it's very easy to make and would take only 20mins, even I used this for the first time,
AVR Programmer
I suggest you to visit Fischl's website for more designs which can be used with the same code available on Fischl's. You can use ATmega48, ATmega8 too.
So, happy burning...